In analysis laboratories, it is necessary to handle large number of samples and to transport them between different process stages and analyzers. The samples are placed in test tubes, which are loaded into and removed from apparatuses such as centrifuges and analyzers. The transport and handling of test tubes may be carried out manually, but various automatic handling systems are increasing in laboratories, due to the increase in the number of samples and the efficiency of analysers. The basic requirements for an automatic conveyor system are the reliable and undamaged handling of test-tubes and the reliable monitoring of the samples in the system. Reliable handling is usually implemented by placing the test tube in a separate transport base, which is guided as it is moved by a conveyor belt along a mechanically delimited track. The position of the test tubes within the system is monitored with the aid of barcodes and code readers and RF chips.
Publication U.S. Pat. No. 5,605,218 discloses a conveyor track, in which the transport base is moved in a U-shaped groove with conveyor bands running in its corners. The bands have a circular cross-section and are arranged to run as parallel continuous loops. Canadian patent application 2,216,052 discloses a system for handling test tubes containing biosamples. In this solution, there are at least two transportation lanes, along which the test tubes, located in transport bases, are moved. EP 0 633 207 discloses a transport system wherein samples are picked from a track with robot arms and transferred to further handling.
Further examples of laboratory automation equipment are described in GB 2 189 884, EP 0 856 736, U.S. Pat. No. 5,370,215, U.S. Pat. No. 5,941,366 and U.S. Pat. No. 5,658,532. Documents EP 0 916 952, DE 43 29 078 and DE 26 44 137 disclose test tube handling methods utilizing rotary deviators.
As the demands for increasing throughput of laboratories increase, demands for increasing transfer speed of the test tubes on the conveyors as well as handling times at various handling stations, are increased. On particular problem in increasing transfer speed or decreasing the cycle time is that acceleration and deceleration of the test tubes becomes harsher. Since liquids in the test tubes move freely and the tubes are often open, acceleration and deceleration as well as tilting or rocking of the test tubes should be controlled so that no spilling of the liquid occurs. Further aspects that are relevant are efficient and reliable detection of test tubes or test tube holders incoming and leaving the handling stations or deviators. One useful aspect would be to decrease the need for stopping the holders and test tubes as then the deceleration and acceleration are greatest.
For the above reasons, it would be beneficial to provide an arrangement and method that provides means for removing a carrier from a deviator to a conveyor without stopping the movement of the carrier.
Further, it would be beneficial to provide a deviator that could process a test tube transported on a test tube carrier by a conveyor so that spilling of the liquid in the test tube is reduced or even prevented.
In a first aspect, the invention relates to a method and apparatus for deviating a test tube transported on a carrier away from the direction of the travel of a conveyor.
According to one aspect of the invention, the invention provides means for force feeding test tube carriers from the deviator to a conveyor.
One embodiment of the invention relates to receiving a carrier with a test tube on a deviator in a manner wherein tilting of the carrier and the tube thereon is reduced or prevented.
According to one further aspect of the invention, the invention provides a method and means for sequencing the test tube carriers coming to a deviator in an efficient manner.
The invention is based on a rotatable deviator that comprises a horizontal deviator plate comprising at least one grip for receiving a test tube carrier and a push plate positioned in proximity of the deviator plate and having at least one pushing surface formed as an arc that starts as a tangent of a circle that the bottom of the recess of the grip travels and then curves outwards from said circle.
According to one embodiment of the invention, at least one push plate is positioned in proximity of the deviator plates of at least two deviators and having four pushing surfaces formed as an arc that starts as a tangent of a circle defined by the track that the bottom of the recess of the grip (21) travels and then curves outwards from said circle.
According to one embodiment of the invention, the deviator comprises at least one contact surface at a distance from the deviator plate and aligned with the grip, the contact surface being formed to contact the test tube carrier at a distance from the contact level of the grip and the carrier.
According to one embodiment, at least the grip is a recess on a circular plate.
According to one embodiment, the contact surface is a recess on a circular plate.
According to one embodiment of the invention, the grip and the contact surface are formed as a part of an arc of a circle.
According to one embodiment of the invention, at least one of the recess of the contact surface or the recess of the grip is an elongated slot.
According to one embodiment of the invention, the grip and the contact surface are formed as a part of an arc of a circle.
According to one embodiment of the invention, the deviator comprises at least two grips and contact surfaces.
According to one embodiment of the invention, the deviator comprises four grips and contact surfaces.
According to one embodiment of the invention the test tube carrier comprises a circular glide plate having a diameter and a thickness, a neck part having preferably a circular cross section, on top of the glide plate, having a length and a diameter smaller than the glide plate and a meshing plate having a diameter and a thickness and being placed at a distance from the glide plate.
According to one embodiment the glide plate comprises a RFID chip and the diameter of the neck part is smaller than the largest diameter of the chip.
According to one embodiment, the carrier comprises a detection surface positioned between the neck part and the meshing plate, the detection surface having a thickness and a diameter smaller than the diameter of the meshing plate and larger than the neck part.
According to one embodiment, the glide plate comprises a seat for a RFID chip to which the chip can be installed from the bottom surface of the glide plate opposite to the neck part so that the chip can be read from the bottom of the carrier formed by the bottom surface of the glide plate.
The invention provides several benefits.
One of the essential benefits of the invention is the possibility to shorten cycle times in various stages of test tube handling, especially at deviators. The test tube carries can be taken to the deviator at greater speed and pushed actively on a conveyor without stopping the movement of the test tube carrier, whereby cycle times can be greatly shortened.
Another beneficial feature is better control of liquid in test tubes, essentially in long and high test tubes. The splashing and spilling of liquid is reduced or avoided. This is important in laboratories where fluid samples of biological origin are handled and danger of contamination is present.
The conveyor system can be easily modified to accommodate various track designs and routes. The system can be built as modules that can be combined together in order to provide a desired automation system for customer's needs. Conveyors, tracks and deviators can be assembled on a simple base plate as a layer structure that provides easy assembly and modifiability.
Other objects and features of the invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are intended solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.